1. Field of the Invention
This invention relates to a water inlet system for a dishwasher and more particularly, a water inlet for a dishwasher which provides for water inlet into the dishwasher and air flow out of the dishwasher to relieve pressure which may occur within the dishwasher.
2. Description of the Related Art
Modern dishwashers include a tub having an access opening and a door for the access opening. The tub supports one or more racks adapted to hold dishes. A pump and liquid spray system is provided for recirculating liquid within the tub. By spraying wash liquid through the tub onto soiled dishes, the dishes are cleaned.
Automatic dishwashers are arranged to carry on a plurality of operations in sequence. The series of operations is generally referred to as a xe2x80x9ccyclexe2x80x9d. A typical automatic dishwasher cycle comprises in sequence a series of operations which may include a first wash, a drain, a second wash, a second drain, a first rinse, a third drain and a final, second rinse followed by a final drain.
At the beginning of each wash and rinse operation, water is supplied into the dishwasher tub. This may be accomplished by controlling a water valve, fluidly interconnected with a water supply, to selectively open and close. A water inlet system must be provided whereby water is directed from the water valve, into the dishwasher tub. A typical water inlet system includes a water inlet device mounted to a side wall of the dishwasher tub which is interconnected with a fill tube which extends from the water valve. The water inlet device serves to direct the water into the dishwasher tub.
Plumbing codes generally require an air gap in association with the water inlet system of a dishwasher so that if a negative pressure is produced in the water supply line, contaminants will not be drawn into the water supply line. Accordingly, water inlet devices for use with dishwashers are configured to provide an air gap which is sometimes referred to as a siphon or vacuum break.
In some dishwashers, the water inlet system has added functionality in that it provides an air inlet path for satisfying various drying, ventilation and pressure surge requirements. In these systems, air may be allowed to pass into and out of the dishwasher tub through the water inlet system.
The present invention is directed to water inlet assembly for mounting adjacent an opening provided in a tub of an automatic dishwasher wherein the tub defines a cavity having a volume for washing dishes. The water inlet assembly includes a housing forming a venting chamber and having an outlet opening mounted in sealed relationship about the opening provided in the tub. The venting chamber is provided with a vent opening. The housing further includes an inlet nozzle for receiving wash liquid and a conduit for guiding liquid from the inlet nozzle to the venting chamber from which wash liquid can flow through the outlet opening into the tub. A water trap is formed into the housing and is located along the conduit. The conduit has a siphon opening located upstream of the water trap. A pressure actuated valve is positioned to block the passage of air from the tub cavity through the venting chamber and out the vent opening in a closed state and to allow the passage of air from the tub cavity through the venting chamber and out the vent opening in an open state. The pressure actuated valve moves from the closed to the open state in response to a rise or a determined excess of air pressure in the tub cavity.